Gas-check pad.



PATENTED APR. 17, 1906.

E. A. YARNBLL.

GAS CHECK PAD.

APPLICATION FILED APR.21,1905.

UNITED STATES PATENT OFFICE.

EUGENE A. YARNELL, OF WASHINGTON, DISTRICT OF COLUMBIA.

GAS-CHECK PAD.

Specification of Letters Patent.

Patented April 17, 1906.

Application filed April 21,1905. Serial No. 256,724.

To all whom it may concern:

Be it known that I, EUGENE A. YARNELL, of Washington, District of Columbia, have invented a new and useful Improvement in Gas-Check Pads, of which the following is a specification.

My invention relates to improvements in the gas-check pads for breech-loading ordnance of the De Bange type, and seeks to overcome certain defects existing in the pads used at'the present time.

The pads now in use consist of a plastic core, usually asbestos and tallow, inclosed in a canvas cover, and this pad is placed between the forward end of the breech-block and a mushroom-head, which latter has a stem passing back axially through the pad and breech-block. The function of this pad is to prevent leaka e of the powder-gases past the breechbloc and out the back end, which would very materially lessen the efliciency of the gun. At the instant the explosion takes place the mushroom-head is forced back against the pad, which is thus caused to expand laterally against the bore of the gun and the stem of the mushroom-head to form a gas-tight seal or gas-check. As the gases which this pad serves to prevent the passage of are at a very high temperature and as the bore of the gun often becomes heated the canvas cover is frequently charred or actually burned to'such a degree as to render the pad absolutely useless.

My improvement is designed to guard against any possible destructlon of the padcover by reason of this high temperature or any disinte ration or loss of the filling material due to long use and rough handling. I accomplish this end without the use of an metallic substance, which would be liable to expand or contract by reason of the great changes of temperature to which it is subjected, and such expansion and contraction would cause the ad to vary in size to such an extent as to render it inelficient. Moreover, the cover is of such durability and closeness of texture that it will be impossible for the filling to work out, and thus in time materially reduce the size of the pad, which would also render it inefficient as a gas-check. This cover is formed of anon-combustible flexible material, which is unaffected either as to size or composition by the extremes of temperature to which it is subjectedsuch, for instance, as asbestos cloth, canvas chemically treated with a ifireproofing composition,

or a cloth formed of cotton and asbestos woven together, the cotton being fi'reproofed and added to give greater strength to the asbestos. 1

My invention will now be pointed out more in detail byreference to the accompanying drawings, forming a art of this specification, and then particular y pointed out in the claims.

Figure 1 represents a section side elevation of my pad on the line 1 1 of Fig. 2. Fig. 2 represents a plan view of my pad as seen from the side which in use is toward the breech-block.

In the drawings, A represents the core or filling material of the pad, which is preferably composed of asbestos fiber and tallow; but I wish it understood that this forms no part of my invention and that any suitable e uivalent may be used. My cover is preferably, although not necessarily, formed of four partsnamely, the two substantially fiat annular pieces B and B, the inner ring B and the outer ring B The two rings are stretched slightly along their edges, laid smooth upon the surface of the core, and the two annular plates securely sewed to the rings along the seams C C 0 G which are pressed so as to form a substantially flat seam. When the pad is thus far completed, it is finished by dipping it in some liquid which would fill the pores of the cloth and cause it to assume a smooth surface impervious to moisture. Melted tallow may be advantageously used, although other material may be found equally satisfactory. If desired or found necessary, the pad may be pressed in a suitable mold in order to give it the proper shape.

One great advantage of the particular form of cover shown is that seams O, 0 and C may be sewed on a machine before the core is put in, thus leaving only seam C to be sewed by hand. This is a great saving in time, as Well as in the expense of manufacture.

Having thus described my invention, What I claim, and desire to secure by Letters Patent, is

1. A gas-check pad having a cover composed substantially of asbestos material.

2. A cover for a gas-check pad, made of a cloth of non-metallic, non-combustible fibrous mineral material.

3. A cover for a gas-check pad made of asbestos cloth.

4. A gas-check pad provided with a suit- I able filling and having a cover formed from an inner ring, an outer ring of asbestos, and two substantially flat pieces connecting said rings.

5 5. A gas-check pad provided with a cover having the portion thereof surrounding the guter periphery ofthe pad composed of asestos.

6. A cover for a gas-check pad formed from a plurality of pieces, the one normally :0 in contact With the bore of the gun being of asbestos.

Signed at Washington, District of Columbia, this 20th day of April, 1905.

EUGENE A. YARNELL. Witnesses:

JNo. WILSON, CARRIE YARNELL. 

